Tire-vulcanizing apparatus



Nov. 24, 1942. w. D. EAKIN TIRE-VULCANIZING APPARATUS 2 sheets-sheet 1 Filed Dec. 25, 19.38

/Nl/ENTOR $55401 r Il',

Nv. 24, 1942. u w, D, EAKlN 2,302,754

TIRE-VULCANI Z ING APPARATUS Filed Dec. 23, 1958 2 Sheets-Sheet 2 Figc 6 INVENTOR @Aw' Mw Patented Nov. 24, 1942 UNITED STATES .PATENT OFFICE 1 Claim.

This invention relates to apparatus for vulcanizing hollow articles such as pneumatic tires.

Heretofore a iiuid-expansible core composed of or comprising rubber, usually called a water bag, for distending the tire in a mold, has been provided with two inlet and outlet pipes, one within the other, one of them being in communication with the manifold of a, chamber type vulcanizer or pot heater and the other having communication with the chamber of the heater, except when the valve is closed, through a valve which opens toward the interior of the bag and is urged toward its open position by a spring, the arrangement being such that when pressure fluid such as steam or water is conducted into the bag from the manifold the air contained in the bag, and steam mixed with it, are driven out through the valve to the interior mold-containing chamber of the vulcanizer until the pressure within the bag is enough greater than that in the vulcanizer chamber to cause the valve to close against the force of the spring.

This arrangement has been employed for ridding the bag of its contained air in order to avoid excessive oxidation of the inner face of the bag in successive vulcanizing operations and in order to avoid the heatinsulating effect of air pocketed in the bag.

In all apparatus of this general type that has been employed prior to my invention, however,

so far as I am aware, either two bag-stems have been employed, at opposite sides of the tire, as in McLeod 1,118,503, with a filler ring closing the opening between the beads of the tire but permitting the pressure uid to Contact the inner face of the tire, which is impracticable because of the ply-separation that occurs in the tire during its vulcanization; or, as in Batcheller 1,175,681, no automatically-closing valve has been employed; or the inlet and outlet openings of the two pipes, in the bag, have been at an elevation half-way up the height of the cavity in the bag, as in Bucyet al. 2,106,627 or Buey et al. Re. 20,561, which has prevented the complete emptying of the bag of curing water or of Water oi condensation by conducting air or steam into the bag; o1', as in a later modification of the Buoy apparatus, a exible pipe adapted to have its open end at a low position in the bag, for venting all of the water down to that low level, has been attached to and in communication with the inlet passage that leads from the interior of the vulcanizer through the spring valve, and Withl the pipe from the manifold opening at a position within the passage just referred to, or Within the extension thereof aiforded by the flexible pipe, with the result that when the pressure in the manifold is released to the exterior of the vulcanizer to permit the valve-spring and the pressure within the vulcanizer chamber to open the valve and thus cause steam from that chamber to enter the bag through the valve-controlled conduit and drive the water out through the manifold the steam has had an open channel for short-cutting directly from the valve-controlled passage into the manifold passage Without ever reaching the free end of the flexible tube, and with the steam jet within the nexible-tube conduit opposing the entrance of water into the flexible tube.

Also, the jet of steam flowing into the bag, from either the vulcanizer chamber or from the manifold, has been so close to the mouth of the water-receiving or air-receiving outlet from the bag, when the flexible pipe has been omitted, that the jet eiect of the incoming steam has caused a suction or fluid-piston effect which, especially when very high velocity has been involved because of carelessness on the part of the personnel, apparently has interferred to a substantial extent with the desired outflow of air, into the heater chamber, at the beginning of the operation, and with the desired outow of water, through the manifold, at the end of the operation.

The chief objects of my invention are to provide improved apparatus of this general type adapted to provide for positive forcing of substantially all of the water from the core at thev end of the vulcanizing operation; to avoid the undesirable suction or fluid-piston action of the fiuid jettng into the bag as above mentioned; to provide a more eective and uniformly dependable washing out of the air from the bag by steam conducted into' the bag at the beginning of the operation even though the incoming jet is very strong and the spring-backed valve is quickly closed by reason of the operator letting steam into the cores more rapidly than is contemplated in the setting of the spring-backed valve for closing at a predetermined difference of pressures on its two sides; and to provide an assembly in which the valve passage and other passages are less subject to being clogged by particles of the bag material than in assemblies heretofore employed.

Of the accompanying drawings:

Fig. 1 is a fragmentary horizontal section of a Vvnlcanizing core embodying my invention in its preferred form, parts being shown in elevation.

Fig. 2 is a fragmentary vertical section of a pot heater assembly embodying the invention.

Fig. 3 is a longitudinal middle section of a valve assembly, heretofore known, which is preferred for employment with other parts of my apparatus.

Fig. 4 is a horizontal middle section of a modication adapted for avoidance of clogging of the passages by crumbs of the bag material.

Fig. 5 is a plan view of a sectional repair core embodying my invention in its preferred form.

Referring to the drawings, the apparatus comprises a uid-expansible core Ill of which a plurality may be assembled in the usual relationship to tire molds II, II and tires I2, I2 therein in a pot heater I3.

Each core is provided with a huid-conducting pipe or stem i4 through which the interior of the bag or core is in communication with the interior of the vulcanizer through a lateral springbacked-valve stem I5 and, within the stem I4, a pipe I6 through which the interior of the bag is in communication with a flexible pipe I1 leading from the jointed manifold I8 of the vulcanizer, which in turn is adapted to be put in communication, selectively, with a steam-supply or gassupply pipe I9 controlled by a valve 2l), a watersupply or gas-supply pipe 2| controlled by a valve 22, or a vent pipe 23 leading to a drain and controlled by a valve 24.

The stem I4 is vulcanized in and thereby sealed to the base wall of the core I, is provided with the usual plates 25, 23 for anchoring it in the rubber of the core, and at its outer end is tted into a head 21 and sealed thereto by a ber washer 21a. Into a side face of the head 21 is threaded the lateral stem I5, and at its outer end the hear 21 is threaded for mating with a bayonet-slot coupling member 2S for attachment to the flexible manifold branch pipe I1.

The spring-backed-valve assembly comprises the lateral stem member I5, formed with a valve seat 29- (Fig. 3) near the inner end of a through passage in which is threaded an apertured springadjusting plug 30 which forms a seat for a compression spring 3I which bears at its inner end against a ball valve 32 to urge the latter away from its seat 23 and toward the inner pipe I6, which latter serves as a stop for the ball. An apertured end cap 33 may be provided for the lateral stem I5.

The inner pipe I6 is permanently mounted in and sealed to the wall of a countersink within the head 21, as shown clearly in Fig. 3, and it is desirable that from time to time the head 21 be unscrewed from the stem I4, permanently anchored in the wall of the bag, for cleaning out of the inner pipe I3 and of the annular space between it and the outer pipe I4.

The necessity of thus removing the head 21 and inner pipe I3 from the stem I4 presented a problem in the matter of having the inner pipe in service communicate directly and positively with a exible tube 34 within the bag, because the flexible tube 34 has to be placed in the bag before its manufacture is completed and remain permanently in the bag and also because the inner pipe It cannot well be made of such size and strength as alone to serve as a mounting for the flexible tube 34.

Having conceived the thought of mounting the flexible tube 33 with its fluid passage as a continuation of the fluid passage of the inner pipe IB, so as to provide a desirable tangential flow of the incoming jet of steam at the beginning of the op..

eration, for washing the air out of the bag at a position sufciently remote from the jet to be substantially out of the region of the suction or fluidpiston effect of the jet, and so as to provide a positive driving out of the water at the end 0f the operation, I have also solved the above-mentioned further problem by mounting the flexible tube 34 upon an elbow 35 which is rigid with and, for convenience of manufacture is screwed upon, a hollow head member 36 which is rigid with and, for convenience oi manufacture is screwed upon, the outer pipe or stem I4, and in its end wall adjacent the elbow 35 is formed with an aperture in which the inner end of the inner pipe I6 is screwed, so that it may be removed for cleaning while leaving the head 36, elbow 35 and flexible tube 34 in place, and yet when in service provides positive fluid connection from the manifold I3 to the interior of the bag through the flexible tube 34, the latter thus being provided with the rugged support of the relatively large pipe I4 and its head which have their support in the Wall of the bag, close to the elbow 35, and not at the remote position of the other end of the weak inner pipe I6. Also, the small inner pipe, having its only other support at the remote position of its other end, is supported and centered by the engagement of its inner end in the threaded aperture of the head 36.

To provide for iiow of iiuid through the annular space between the two pipes I6, I4 and through the spring-backed valve assembly, outward from the bag for the washing out of air at the beginning of the operation and into the bag for driving water out through the flexible tube 34 and through the manifold I8 at the end of the operation, the head 36 is formed with apertures 31, 31.

The stem I4 may be provided with the usual anch-orage plates 25, 26 and the flexible tube 34 may be provided with the usual metal nozzle 40 at its free end for directing incoming fluid tangentially in the bag and to serve as a weight for assuring that its mouth Will be at the lowermost part of the bag cavity for conducting out substansprings 3 i the pressures preferably being so controlled that the valves close only after substantially all of the air has been washed out of theY bags.

The vulcanization of the tires is then carried` out in the usual way, with either high pressure steam or high pressure water, conducted in.

through the manifold I8, holding the tires distended in their molds.

At the end of the cure the interiors of the bags are vented through the flexible tubes 34 and the manifold I8, some of the water in the bags flashing into steam and exerting an expelling force upon the remaining water, and when the pressure within the bags is suiiiciently lower than that within the heater chamber the valves 32 are opened by the force of the springs 3I acting in addition to the chamber pressure and steam from the chamber enters the bags through the opened valves and by positive static pressure drives substantially all of the water from the bags throughv the flexible pipes 34 and the manifold I8, the free end of the Iiexible tube 34 of course lying upon the bottom wall or floor of the bag, as shown clearly in Fig. 2.

In the modication shown in Fig. 4 the outer stem, |45, has the exible pipe 34 mounted upon and sealed to a head I4b which is mounted upon the inner end of the stem Ma, with no direct communication between the exible tube and the small inner pipe, I6a, and at its outer end the outer stem, I4, is threaded into a pipe-T, 21X, which has the bayonet-slot coupling, 28a, threaded into its laterally-extending arm, for communication of the manifold with the annular outer passage instead of with the inner passage of the small inner pipe as in Fig. 1.

The small inner pipe I6 is at its inner end threaded through a wall of the head |4b, thus leading directly into the interior of the water bag, and not through the flexible pipe 34 as in the prior art.

At its outer end the small inner pipe Ih*1 is fitted and welded in an annular recess formed in a head 215 and the latter, having in axial extension thereof a valve assembly such as is shown in Fig. 1, is adapted to be drawn onto and sealed to a pipe 212, which is screwed into the adjacent arm of the pipe-T 21X, by rotating the head 21y to screw the inner end of the small inner pipe I6a into the wall of the head l4b, a fiber washer 21m and a metal washer 21x1 being interposed between the pipe l1Z and the head 21V.

This construction segregates, and thus renders less subject to clogging, the bottle-neck factors represented by the narrow annular passage through the valve-seat, past the ball, and the narrow annular passage between the small inner pipe 16a and the outer stem |42.

Also, by reason of the fact that the Valve assembly is an axial extension of the passage in the small inner pipe, with a substantially straight W of uid through them, this construction avoids the centrifugal-separator, clogging elTect, or eddies incident to the right-angle turn, close to the valve-seat, in Fig. 1.

The annular passage between the two pipes gets an effective reverse-flow cleaning eiect in each vulcanizing cycle, without hindrance to or hindrance by the narrowness of the annular valve passage, and in each vulcanizing cycle the valve passage gets an eiective reverse-110W cleaning eiect without hindrance to or hindrance by the narrowness of the annular passage between the pipes, and the right-angle turn of the current, in the pipe-T, in crumb-carrying outow, is into the branch pipe from the manifold, which is of course much less subject to clogging than the narrow annular Valve-passage is, so that the centrifugal-separator eiect of the eddies is harmless.

Various other modications are possible within the scope of the appended claim and the invention is not wholly limited to use in an assembly including a vulcanizer of the pot heater type.

I claim:

Tire-vulcanizing apparatus comprising an expansible core, a single core-stem therefor having two inlet-outlet passages one within the other, and, within the core, a tube having an open end at substantially the lowest part of the core cavity, the said tube at its other end having fluid connection substantially with only the outer one of the said passages, and a spring-opened, inwardly-opening valve having its passage as substantially an axial extension of the inner passage.

WILLARD D. EAKIN. 

